Chelsea are the favourite to win what looks to be another thrilling and open race for the Premier League title. The thinking is that the team with the best defence last season now has the added flair of Cesc Fabregas and the goals of 32 million pound Diego Costa.

Perhaps, too, Jose Mourinho's confidence that his "little horses" have grown into Derby winners is proving infectious. But Costa will be vital, and if he fails to settle or repeats his awful World Cup form, then Chelsea's big gamble will look like a poor investment.

Certainly for this observer, Chelsea's chances are no better than those of Manchester City, Liverpool or Arsenal.

City won the crown last season despite compulsive scorer Sergio Aguero starting only half the side's games. If he can shake off a series of injuries, it is hard to imagine the champions being anything but deadly around goal, remembering they struck 102 times in the league last term.

But City followed their last title win with a limp defence, and you wonder if the same might happen again.

The arrivals of Diego Costa and Cesc Fabregas have turned Chelsea into a title favourite.

Manuel Pellegrini has spent 32 million pounds on Porto defender Eliaquim Mangala, but the 23-year-old is France's fourth-choice centre-back. Scouts have said he is strong and quick but not yet the finished article and prone to lapses in concentration. Yet having spent that much, City will presumably start him ahead of Martin Demichelis, whose form in Brazil made mugs of his many critics.

City have the talent to retain their crown, but does this group have the mentality to start a Ferguson-style dynasty?

Many are writing off Liverpool now that Luis Suarez, provider of 31 goals and 12 assists last season, is gone.

Brendan Rodgers signed 80 million pounds' worth of talent to give his squad the depth to cope with a return to the Champions League. The most important of the fresh faces might be Croatian Dejan Lovren, who is charged with plugging the leaks in a defence that conceded 50 goals last season -- far too many for any team with title aspirations.

Based on the admittedly flimsy evidence of a 4-0 friendly win over Borussia Dortmund on Sunday, Lovren might be the commanding leader the Reds have been lacking since Jamie Carragher's retirement.

Expect the signing of another striker to aid Daniel Sturridge, while Raheem Sterling, Philippe Coutinho -- brilliant against the Germans -- and Adam Lallana can cause enough mischief even without Suarez.

Liverpool have the potential to go close again, especially if the confident Lovren continues to look like a new Carragher.

I would like Arsenal's chances more if they had managed to get Sami Khedira from Real Madrid. The need for a strong, dynamic holding midfield man is acute because it really is not Mikel Arteta's forte.

Goals and creativity will not be a problem, with Alexis Sanchez being a great addition and Theo Walcott returning in the autumn to add even more pace. But having lost the underrated Bacary Sagna and adding Mathieu Debuchy and Calum Chambers, are Arsenal really any better equipped to avoid some of the hammerings they took against their main rivals last season?

How much stronger will Arsenal be with new signing Mathieu Debuchy playing right-back rather than Bacary Sagna?

Manchester United surely will improve with the experienced and utterly self-confident Louis van Gaal striking a fear factor into a squad that hardly helped David Moyes a year ago. But while Ander Herrera and Luke Shaw look like good signings, much more needs to be done before Aug. 31.

A right wing-back, another midfield man and a top central defender are all required for a team that has lost old soldiers in Rio Ferdinand, Nemanja Vidic, Patrice Evra and Ryan Giggs, while Michael Carrick is out until October. United will do well to make the top four unless they can capture Angel di Maria and a few others.

Some kind early fixtures could give United their mojo back, and the switch to 3-5-2 looks set to get the best from Juan Mata playing just behind Robin van Persie and new captain Wayne Rooney.

Everton also have top four ambitions under the bright and innovative Roberto Martinez, and the 28 million pound investment in Romelu Lukaku is a statement of intent. Expect another bold show.

As for Spurs, little has happened to inspire belief that they can gate crash the top four.

At the odds advertised, Liverpool are tempting at 14-1.

Ian Darke, who called games for the network during the 2010 and 2014 World Cups, is ESPN's lead soccer voice in the U.S. Reach him on Twitter @IanDarke.